Pickup, transport and precise placement of small articles normally includes use of a vacuum head for engaging and releasing the transported article. Such apparatuses are commonly referred to as pick and place mechanisms.
Some pick and place mechanisms include a pneumatic cylinder which drives a spindle mounting a vacuum head on a free end thereof. The spindle is advanced and retracted as required along its own axis, to pick up or place the articles (components), and is transported in a plane normal to the axis of the spindle to move the components from one location to another. Pneumatically operated devices are accompanied by substantial disadvantages inherent in pneumatic operation. Some drawbacks are the difficulty in monitoring the spindle position along its axis, and excessive size, particularly when the component is quite small.
Known pick and place mechanisms include, for example, U.S. Pat. No. 5,278,634 to Skunes, U.S. Pat. No. 6,145,901 to Rich, U.S. Pat. No. 4,860,438 to Chen, U.S. Pat. No. 4,595,335 to Takahashi, U.S. Pat. No. 4,151,945 to Ragard, U.S. Pat. No. 8,068,664 to Rudd and European patent application publication 0235045 A2 to Universal Instruments Corporation.